“One of the problems that a lot of people like myself, we have very high levels of intelligence but we’re not necessarily such believers,” Trump said. “You look at our air and our water and it’s right now at a record clean.”

On the issue of whether global warming is caused by humans, Trump added: “As to whether or not it’s man-made and whether or not the effects that you’re talking about are there, I don’t see it — not nearly like it is.”

But Trump said the air quality in places like China, Russia and South America is “incredibly dirty,” an apparent acknowledgement that different countries have looser environmental standards.

“And when you're talking about an atmosphere, oceans are very small. And it blows over and it sails over,” he said. “I mean, we take thousands of tons of garbage off our beaches all the time that comes over from Asia. It just flows right down the Pacific, it flows, and we say where does this come from.”

The comments come days after his administration published its first National Climate Assessment, which found that climate change could upend daily life for many Americans as it takes a toll on infrastructure, human health and the world's energy supply. It also said current and global and regional efforts are not enough to reverse the trends.

Trump, who decided last year to withdraw from the Obama-era Paris climate accord, has previously criticized the report, and his top aides have said its warnings are overheated.

White House press secretary Sarah Huckabee Sanders told reporters on Tuesday that the report is “not based on facts” and because the science behind climate modeling “is never exact.”

“The president’s certainly leading on what matters most in this process, and that’s on having clean air, clean water,” Sanders said. “In fact, the United States continues to be a leader on that front.”

The Fourth National Climate Assessment report, which was mandated by the Global Change Research Act of 1990, says “observational evidence does not support any credible natural explanations” for the rise in global temperatures.

"The warming trend observed over the past century can only be explained by the effects that human activities, especially emissions of greenhouse gases, have had on the climate," it reads.

Asked a day earlier about the devastating projections in his administration’s report, the president dismissed them.